&SIGNAL: PLOT-FIELD: functions
The induced charges are computed by first calculating a
drift line of the requested type and then integrating the
internal product of drift velocity and weighting field
over the drift line. The charge thus obtained is multiplied
with the charge of the particle that has been drifted.
The charge should be +1 or -1 for a particle drifting from
the read-out electrode to another conductor and 0 for a
particle that drifts between conductors that are not read
out.
The charge induced over a given path should, apart from the
sign, should not depend on the type of particle that drifts.
However, in the presence of a magnetic field, electrons and
ions will in general follow different paths, may therefore
end up at different points, and hence induce different charges.
Charges are expressed in multiples of the electron charge.
The status codes are the numeric status codes:
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Status End of drift line Numeric code
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Left area Left the drift area -1
Too many steps More than MXLIST steps -2
Abandoned Various faults -3
Hit a plane Hit an equipotential plane -4
Left drift medium Entered a dielectricum -5
Left mesh Left the finite element mesh -6
Hit an X wire Hit a wire of type X 1 to MXWIRE
Hit an X wire replica Hit a replica of an X-wire MXWIRE + (1 to MXWIRE)
Hit an X solid Ended in a solid of type X 2*MXWIRE + (1 to MXSOLI)
Unknown Other cases (shouldn't occur) other
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The times are the total drift time for particles of the
selected type from the position at which the function is
to be evaluated until the particle leaves the AREA, hits
an electrode, exceeds the maximum number of steps, is
abandoned etc.
The times are expressed in microsec.
The weighting field is the field with which the drift
velocity of a moving charge is multiplied to obtain the
current induced in the various electrodes.
There is one such field per electrode or per group of
sense wires.
This field is computed by setting the read-out electrode
to unit voltage and earthing all other conductors.
The unit of the weighting field is 1/cm.
Keyword index.
Formatted on 10/11/98.